HR: 0800h
AN: SM31C-0575    [Abstracts]
TI: Cluster Observations and Kinetic Simulations of Slow Mode Shocks at the Earth's Bow Shock
AU: * Kucharek, H
EM: Harald.Kucharek@unh.edu
AF: University of New Hampshire, 39 College Road, Durham, NH 03824, United States
AU: Mouikis, C
EM: Chris.Mouiks@unh.edu
AF: University of New Hampshire, 39 College Road, Durham, NH 03824, United States
AU: Scholer, M
EM: mbs@mpe.mpg.de
AF: Max-Planck-Instiut f. Extraterrestrische Physik, Giessenbach Strasse 1, Garching, 85740, Germany
AU: Eriksson, S
EM: eriksson@lasp.colorado.edu
AF: University of Colorado, Boulder, 1234 Innovation Drive, Boulder, CO 80303, United States
AB: Slow shocks in association with reconnection are thought to be the main engine of the plasma heating, acceleration and dynamical changes of the magnetosphere. It is therefore very important to study their structure and the related physical processes. Measurements, from CLUSTER spacecraft show clear evidence for slow- mode shocks associated with magnetic reconnection in the near Earth magnetotail in connection with a substorm onset [S. Eriksson et al., 2004]. Most of the knowledge of slow mode shocks was derived from two-fluid theory together with extensive small-scale hybrid simulations of the shock transition. However, it is difficult to perform numerical simulations under realistic plasma conditions. First, it is important to use realistic proton electron mass ratios to study downstream electron heating. Second, the method to initiate a slow mode shock is Might have an impact of the obtained results. Using the piston method the slow mode shock will run into the downstream region of a preceding fast shock wave. Using switch off shock conditions the slow mode shock will run into a quite plasma environment. However, at the Earth's bow shock turbulence will always be around. Finally, dimensional effects in numerical simulations have effects on the results. For instance in 1D simulations all wave vectors are forced in the simulation direction. Furthermore, full particle simulations predict lower downstream ion temperature than predicted by hybrid simulations. This is attributed to electron kinetic processes. We performed a number of 1D full particle simulations with real proton to electron mass ratio and multi-dimensional hybrid simulations to address the above-mentioned topics. As input for the numerical simulations we used plasma- parameters from the established Cluster database. We investigated the dynamics, the structure, and the evolution of the simulated slow mode shocks using the piston and the "switch-off" method for hybrid and the 1D full particle simulations. Furthermore, we investigated the impact of the proton/electron mass ratio and compared these results with Cluster observations.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2753 Numerical modeling
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting